As PhillS pointed out in a comment, the matter of what it takes to kill a person is a matter of biology/physiology, not physics. So in general, we consider questions asking how to kill a person (or kill an animal, cause brain damage, break a bone, shrink a tumor, etc.) off topic because there is a significant component of them that is not physics.
The way to handle these sorts of questions is to break them up into a biology part and a physics part. In your case: respectively, (1) how much current does it take to kill a person, and (2) how can I tell how much current can be generated from a 1.5V battery? The biology part you can take to the corresponding SE site, though there's no guarantee they will accept it there. As for the current question, you could try to ask here how to determine whether it's possible to produce a certain amount of current from a battery, but even that is kind of on the engineering side, and may still be considered off topic. If you did some research to try to figure out yourself how much current can be produced from a battery, you could ask about some of the physics concepts you encounter in that research, and those sorts of questions would be much more likely to be on topic.
Good of you to come to meta to ask why your question was voted off topic, by the way. We always like to see people considering the community's feedback on their questions, and staying involved.
P.S. Now that I look at it again, the style in which you wrote the question is also not the best, but that's not such a big deal.